Gases containing volatile aroma constituents are evolved during one or more stages of processing beverages such as coffee, tea, and cocoa. For example, in coffee processing, gases containing aroma constituents are given off during a number of stages of the processing operation, such as during roasting of whole beans, grinding of the roasting whole beans, extraction of water solubles, steam distillation and the like. It has been recognized that the aroma and flavor of such beverage products, particularly soluble coffee products, can be improved by recovering the aroma gases and incorporating them in the beverage product, such as by addition of the aroma constituents to coffee extract prior to drying or to the dry powder or granules. Frequently coffee aroma gases are recovered by low temperature condensation of the gases at liquid nitrogen temperatures to form a coffee aroma frost. A number of procedures have been suggested heretofor for the recovery of coffee aroma frost. One such procedure which is widely used involves condensing the aroma gases on the walls of a scraped-surface heat exchanger which is cooled by means of liquid nitrogen. The condensed gases are scraped from the walls and collected at the bottom of the heat exchanger in the form of a frost or snow which is recovered. However, this procedure is inefficient and is subject to a number of disadvantages. For example, the total gas stream entering the heat exchanger is not necessarily entirely cooled down and fine frost particles tend to become entrained in the gas stream and leave the heat exchanger without being caught.